Consumers are often woefully ignorant of basic facts about food and agriculture. For example, in this paper I published with Brandon McFadden, we report multiple lines of evidence that most people know very little about genetically engineered food. When scientific names are used for food ingredients (e.g., sodium chloride instead of salt), perceptions of naturalness and safety substantially decline. A typical response to these sorts of findings is, "we need to spend more on consumer education." Such a statement is an implicit endorsement of the knowledge deficit model - it is a view that "experts" convey the information, consumers accept it and update their beliefs accordingly.
Dan Kahan's work on cultural cognition had gone a long way toward dismantling the knowledge-deficit model of how consumers change opinions. His work shows that "more education" doesn't necessarily lead to convergent beliefs; rather, it seems we filter information through our group identities. I recently ran across a book chapter Kahan wrote, and thought I'd share the abstract as it does a good job describing why consumers (and scientists) may not be fully informed and how we might change their minds on controversial issues.